Pothead device



Jan. 26, 1937.

| H. THULLEN POTHEAD DEVICE Original Filed Nov. 14, 1929 Patented Jan. 26, 1937 UNITED STATES PATENT OFFICE POTHEAD DEVICE Application November 14, 1929, Serial No. 407,074

- Renewed October 22, 1934 11 Claims. (01. 173-353) This invention relates to electrical conductors in general, and more particularly to pothead devices such as are used for connecting electrical cables with overhead conductors.

Pothead devices usually include a tubular insulation member for receiving an electrical cabl-e. This insulation member is provided with an upper or outlet end in the form of a metallic contact element adapted to be contacted by an overhead conductor. This contact element is electrically attached to the end of the cable within the insulation member and the inlet end'oi the insulation member is so connected and attached to the cable as to support the same through the intermediary of its sheath. The cable is adapted to expand and contract longitudinally depending largely upon the amount of current-passingtherethrough. In order to take the strain 01! of the insulation member and prevent cracking thereof, usually near the "top, as the cable expands and contracts, it ishighly desirable to provide some means for yieldably connecting the upper end of the cable to the insulation member, and it is accordingly the primary object of this invention to provide such a connection.

Another object of this invention is to provide such a connection and associated parts of a pothead, which may be economically manufactured, which will be rugged of operation and convenient of assembly, inspection, renewal or repair.

Other and further objects of this invention will be apparent as the same becomes better understood from an examination of the specification and claims in connection with the accompanying drawing, wherein- Fig. 1 is a fragmentary elevation of a pothead embodying this invention;

Fig. 2 is a fragmentary vertical section of the same; and

Fig. 3 is an enlarged horizontal section taken at the line 3-4 of Fig. 1.

Referring to the drawing more particularly, reference character 4 designates a tubular insulation member provided with an opening It at its upper end and closed at its lower end by a suitable closure or housing 6. This closure or housing 8, so far as this invention is concerned, may be of standard form permitting the entrance of a cable 1 into the lower end of the member 4 and providing for the support of said cable through the intermediary of the sheath (not shown) in said member 4, whereby oil or other compound therein may enter the sheath and surround the wrapping of the cable to keep such wrapping in efficient condition and whereby the upper end of the cable may be connected to a suitable contact or terminal member generally designated by the reference character 8 and which will be more particularly described hereinafter. Although the closure or housing 6 providing for the support of o the cable in the inlet of the pothead may be of standard form, it is preferably as illustrated and described in the co-pending application of George P. Edmonds for Pothead devices, filed August 13, 1929, bearing Serial No. 385,641.

The upper end of the cable I is in the form of a male plug 9, which fits in a suitable socket in the lower end of an extension II. This extension member acts to electrically connect the end of the cable to a combined cover and contact mem- 1o ber l2, said extension being provided with a threaded upper portion II which is threaded to said cover.

The combined cover and contact member, to gether with the extension ll forming the terminal member 8, are connected to the upper end of the insulation member 4 through the intermediary of a cylindrical member l4 which is in the form of an expansible and contractible metal- The lower end of the bellows I4 has its brim sweated to the inner periphery of a cylindrical member i9, which is provided with a circular flange 2| engaging an inner shoulder 22 in the member 4 at the bottom of the opening 5. This member "I9 is provided with a nut 23 for compressing the flange 2| against the shoulder 22 through the intermediary or a washer 24 for forming a non-leakable Joint and for supporting said member in the opening 5, a washer 26 being also provided between the nut and the upper end of the member 4.

In order to prevent rotational movement of the extension H and possible working loose thereof in consequence of such movement, the same is provided with angularly spaced laterally extending integral earsIi, which are adapted to engage with inwardly extending integral ears 2'! formed in the inner periphery of the member II. V

In order to facilitate the renewal 01' oil within 5 the pothead the member I6 is tapped and provided with threaded plugs 28 which may be removed to admit oil through openings 29 to the interior oi. the pothead.

The housing or closure 6 is attached through the intermediary of bolts 3| to ring 32 cemented to the lower end or the member 4. A bracket 93 is bolted to the lower end of the housing 6 and this bracket is provided with a suitable clamp (not shown) for supporting the pothead.

It will be apparent that whenever the cable I longitudinally expands or contracts, the bellows 29 will permit relative movement of the terminal or contact element 8 with respect to the insulation member 4 without danger of breaking the connection between said terminal member and insulation member. It is also to be noted that the connection between the terminal or contact member 8 and the insulation member oflered by the bellows l4 and the annular members i5 and I9 by means of which the bellows is attached to the members 8 and 4, respectively, is a nonleakable connection.

The other advantages of the aforedescribed construction will be apparent without Iurther description.

I am aware that many changes may be made without departing from the principles of this invention and I therefore do not wish to be limited to the details shown or described.

What I claim is:

1. In a device of the character described, the combination of a cable and a tubular insulator member adapted to enclose the upper end or said cable, a cylindrical expansible member adapted to be connected at one end to the insulator member and at the other end to the cable, and means for connecting the ends of said expansible member to the parts to which they are adapted to be connected, said means including a shoulder on the insulator member, an annular member provided with an annular flange, a washer between the said shoulder and flange, and a second member movable relative to the flange for clamping said washer to form a non-leakable connection between one end of said expansible member and the part to which it is connected.

2. In a device of the character described, the combination of a cable and a tubular insulator member adapted to enclose the upper end of said cable, a cylindrical expansible member arranged to permit relative longitudinal movement between the end of said cable and said insulator member; a cable terminal, a circular member attached to the upper end of said cylindrical expansible member, a cylindrical flanged member attached to the lower end of said expansible cylindrical member, means for engaging the said cylindrical flanged member on the insulator, and means for engaging the said circular member to the cable terminal.

3. In a device of the character described, the combination of a cable and an interiorly flanged tubular insulator member adapted to enclose the upper end of said cable, a flanged cylindrical member removably attached to the insulator to engage the said insulator flange, a terminal fltting secured to the upper end of the cable, an expansible cylindrical member associated with the said flanged cylindrical member and the said terminal fltting to permit their relative longitudinal movement; inwardly projecting ears l on the flanged cylindrical member and outwardly projecting ears on the terminal fitting, said ears arranged to interlock so as to prevent relative rotational movement but to permit relative longitudinal movement or the cable and-the insulator member.

4. In a device of the character described including a cable, a tubular insulator member and .5

an expansible and contractible tubular member in the form of a bellows having means for connecting the said cable and the said insulator, said means comprising a metal fitting rigidly and hermetically secured to the top of the expanslble member and screw-threadedly secured to the cable terminal, a second metal fitting in the form of a hollow bolt rigidly and hermetically secured to the bottom of said expansible member and nut means bearing on the top of the insulator member for mechanically securing said fitting to said insulator member.

5. A device of the class described, comprising a tubular insulator having a flange defining an opening at one end thereof, a cable extending Si into said opening and having a terminal extend ing through said opening, a connecting unit for flexibly connecting said cable terminal to said insulator and for closing the opening thereof, said unit comprising an expansible and contractible member surrounding said terminal, a sleeve connected to said expansible and contractible member to form a permanent connection therebetween in the assembly under normal con ditions and having a flange in abutting relation with the flange of said insulator, and means for holdingsaid flanges in said abutting relation I whereby said sleeve is secured to said insulator, and means secured to the other end of said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions and secured to said cable terminal to provide a readily detachable connection therebetween in the assembly under normal conditions.

6. A device of the class described, comprising .a tubular insulator havinga flange defining an opening at one end thereof, a cable extending into said insulator and having a terminal extending through said opening, a connecting unit for flexibly connecting said cable terminal to said insulator and for closing the opening thereof, said unit comprising an expansible and contractible member surrounding said terminal, a sleeve connected to said expansible and contractible mem- 50 ber to form a permanent connection therebetween in the assembly under normal conditions and having a flange in abutting relation with the flange of said insulator, a lock nut adjustably mounted on said sleeve and in abutting relation 55 to said insulator to draw said flanges into abutting relation whereby said sleeve is secured to said insulator, washers between said insulator, sleeve and lock nut to provide a fluid tight joint between said sleeve and insulator, and means secured to the other end of said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions and secured to said cable terminal to provide a readily detachable connection therebetween in the assembly under normal conditions.

7. A device of the class described, comprising a tubular insulator having a flange defining an' opening at one end thereof, a cable extending 7 into said insulator and having a terminal extending through said opening, a connecting unit for flexibly connecting said cable terminal to said insulator and for closing the opening thereof, said unit comprising an expansibie and contracti- 1 ble member surrounding said terminal, a sleeve connected to said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions and having a flange in abutting relation with the flange of said insulator, means for holding said flanges in said abutting relation whereby said sleeve is secured to said insulator, and a member secured to said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions, said member embracing said cable terminal, and means for securing said last-named member to said terminal to provide a readily detachable connection therebetween in the assembly under normal conditions.

8. A device of the class described, comprising a tubular insulator having a flange defining an opening at one end thereof, a cable extending into said insulator and having a terminal extending through said opening, a connecting unit for flexibly connecting said cable terminal to said insulator and for closing the opening thereof, said'unit comprising an expansible and contractible member surrounding said terminal, a sleeve connected to said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions and having a flange in abutting relation with the flange of said insulator, a lock nut adjustably mounted on said sleeve and in abutting relation to said insulator to draw said flanges into abutting relation whereby saidsleeve is secured to said insulator, washers between said insulator, sleeve andlock nut to provide a fluid tight joint between said sleeve and insulator, and a member secured to said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions, said member embracing said cable terminal, and means for securing said last named member to said terminal to provide a readily detachable connection therebetween in the assembly under normal conditions.

9. A device of the class described, comprising a tubular insulator having a flange defining an opening at one end thereof, a cable extending into said insulator and having a terminal extending through said opening, a connecting unit for flexibly connecting said cable terminal to said insulator and for closing the opening thereof, said unit comprising an expansible and contractible member surrounding said terminal, a sleeve connected to said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions and having a flange in abutting relation with the flange or said insulator, means for hold-v ing said flanges in said abutting relation whereby said sleeve is secured to said insulator, a member secured to said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions, said member embracing said cable termiml and means for securing said last named member to said terminal to provide a readily detachable eonnection therebetween in the assembly under normal conditions, and means on said sleeve and said terminal for limiting rotation of said terminal in respect to said insulator but permitting relative movement of translation between said terminal and insulator.

10. A device of the class described, comprising a tubular insulator having a flange defining an opening at one end thereof, a cable extending into said insulator and having a terminal extending through said opening, a connecting unit for flexibly connecting said cable terminal to said insulator and for closing the opening thereof, said unit comprising an expansible and contractible member surrounding said terminal, a-sleeve connected to said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions and having a flange in abutting relation with the flange of said insulator, a lock nut adjustably mounted on said sleeve and in abutting relation to said insulator to draw said flanges into abutting relation whereby said sleeve is secured to said insulator, washers between said insulator, sleeve and lock nut to provide a fluid tight joint between said sleeve and insulator, a member secured to said expansible and contractible member, said member embracing said cable terminal and means for securing said last named member to said terminal to provide a readily detachable connection therebetween in the assembly under normal conditions, and means on said sleeve and said terminal for limiting rotation of said tenninal in respect to said insulator but permitting relative movement of translation between said terminal and insulator.

11. A device of the class described, comprising a tubular insulator having a flange defining an opening at one end thereof, a cable extendinginto said insulator and having a terminal extending through said opening, a connecting unit for flexibly connecting said cable terminal to said insulator and for closing the opening thereof, said unit comprising an expansible and contractible member surrounding said terminal, a sleeve connected to said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions and having a flange in abutting relation with the flange of said insulator, a lock nut adjustably mounted on said sleeve and in abutting relation to said insulator to drawsaid flanges into abutting relation whereby said sleeve is secured to said insulator, washers between said insulator, sleeve and lock nut to provide a fluid tight joint between said sleeve and insulator, a member secured to said expansible and contractible member to form a permanent connection therebetween in the assembly under normal conditions, said last named member embracing said cable terminal, and means for securing said last named member to said terminal to provide a readily detachable connection therebetween in the assembly under normal conditions, and a washer disposedbetwe'en said terminal and said last named member to provide a fluid tight joint therebetween.

LOUIS H. TI-IULLEN. 

